The present invention relates to electrical connectors and more particularly to interconnections made between a multi-layer printed circuit board and a high speed coaxial cable.
The interconnection of integrated circuits to other circuit boards, cables, or other electronic devices is well known in the art. As the speed of the electronic devices increase, there is a growing need to design and fabricate printed circuit boards and their accompanying interconnects with closely controlled electrical characteristics to achieve satisfactory control over the integrity of the transmitted signal. The extent to which the electrical characteristics (such as impedance) must be controlled depends heavily upon the bandwidth of the circuit. That is, the faster the signal rise-time, the greater the importance of providing an accurately controlled impedance within the interconnect.
Because of their favorable electrical characteristics, coaxial cables and connectors have grown in popularity for high performance systems. As is known in the art, coaxial connectors provide an inner or signal conductor coaxially disposed within an outer conductor, with a dielectric material disposed therebetween. It is well known to mount coaxial connectors on a printed circuit board, with the signal conductor electrically connected to a signal circuit of the printed circuit board and the outer conductor electrically connected to a ground circuit of the printed circuit board. The electrical connections between the coaxial connector and the printed circuit board are typically made by soldering. Examples of such connectors can be seen, for example, in U.S. Pat. No. 4,650,271.
However, coaxial cable connectors are relatively bulky in comparison to other pin and socket type connectors. The size of currently available coaxial connectors makes it extremely difficult, if not impossible, to mount a large number of connectors on the limited space of a typical printed circuit board. A need thus exists for a coaxial cable connector assembly that allows multiple coaxial cables to be connected to a printed circuit board using less space than traditional coaxial cable connectors, while maintaining the sought after performance of the coaxial system. In addition, it is desired that such a connector could be used with current assembly technology, such as pick and place equipment.
The invention described herein is a connector assembly which may be attached to a printed circuit board and which provides multiple coaxial connectors in a package which is more compact and easier to assembly than currently available coaxial connectors. The connector assembly uses a plurality of dielectric insulators which are integrally formed with each other. The individual insulators are spaced from each other by a web member. A signal pin or conductor is positioned coaxially within each insulator, and a ground or shield tube is positioned concentrically around the signal pin and shield tube. Because the plurality of insulators are positioned at a predetermined spacing, the signal pins and shield tubes may be gang-loaded on the insulators. An external housing member may be provided for the plurality of insulators. Preferably, such external housing is integrally formed with the plurality of insulators.